noises

Question
My guinea pig after eating a meal his stomach seems to make a noise as if he is hungry. But he just got done eating. This just started about a month ago. He is 2 years old. And even after having his dinner the same thing happens. Oh and I can't forget, sometimes during the night after going to bed, I hear his stomach making that same noise. There doesn't seem to be anything wrong with him. Any help would be greatly appreciated. Thank you!

Answer
it could be a grunt which does seem to radiate from deeper inside the animal, and tends to be louder from boars, i would not worry too much unless it seems to happen when he gets excited, if this is the case then it might be a respitory problem caused by his floor shavings.